Real pretty small alu welds??

I'm no expert, but I would try using a lot more amperage, 130-150, and maybe a bigger electrode, 1/8". I would then floor the pedal until the puddle formed, then back way off on it as you move across...

You need to pour the heat on at the start with aluminum as it is so conductive...

Thats the hardest thing I had to learn about welding aluminum. With steel, I tend to creep up on it till I get a puddle. With Aluminum...I was getting meltdowns and having the bottom of an unsupported area Spluge onto the welding table rather unexpectedly after heating and heating and heating. I dont know if its wrong..but for me..at this point in my amature welding..I set the Start Current to about 90%, and hit it hard from the gitgo..tapering off as things start to puddle and flow.

Gunner, who would take a class if there were any available in his area.

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner

As an amateur I find that I get the best result starting a bead by pre-heating with the arc, then putting a bit of filler down. Then, I flow the bit of filler into a puddle and get both parent pieces engaged in the puddle. I don't wait to get a puddle started before I add the filler - I add the filler first. I just finished a seat for my race car that is in .062" AL, and I did about 4 feet each of inside and outside fillet without a single drop-through - surprised the heck out of myself...

I also (using 3/32 tungsten etc) ground a very short blunt taper, and that seemed to help keep the arc from wandering.

Brian

I know nothing about welding aluminum, but this sounds like a good application for brazing. The filler will wick in between the bars, give you a really strong joint, and still be barely seen, with no indication at all that there was a weld of any kind. Isn't that what you want? If only one side is visible, why not do plug welds around the outside and say diagonally a couple places?

I never thought of this, probably because I never brazed aluminum. Have you done this? How about the prep work??

Thanks Uwe

I know nothing about brazing aluminum. Hopefully someone else will weigh in on it.

| > I know nothing about welding aluminum, but this sounds like a good | > application for brazing. The filler will wick in between the bars, give you | > a really strong joint, and still be barely seen, with no indication at all | > that there was a weld of any kind. Isn't that what you want? | > If only one side is visible, why not do plug welds around the outside | > and say diagonally a couple places? | >

|

Don't think it can be done. The chart I'm looking at lists the melting point of aluminum alloys in the 1,100-1,200 F range and the melting point of brasses in the 1,800-1,900 F range. Rather the opposite of what you need for successful brazing.

Pete C.

| > I know nothing about brazing aluminum. Hopefully someone else will | > weigh in on it. | >

| | Don't think it can be done. The chart I'm looking at lists the melting | point of aluminum alloys in the 1,100-1,200 F range and the melting | point of brasses in the 1,800-1,900 F range. Rather the opposite of what | you need for successful brazing. | | Pete C.

Not welded with bronze, welded with special rod made for brazing aluminum. I've never had a need to use it myself, but there's the folks at trade and auto shows hawking it by brazing up pop cans and such, and a quick peek at the web gives me gobs and gobs of sites that sell aluminum brazing rod. Supposedly you can even use your propane torch, which is why they hawk it to backyard mechanics and such.

You use a aluminum brazing alloy. Such as Alloy 31 from Esab. It's melting point is a little lower than most alloys. It works super well on things like car A/C condensers. Actually it's what they use to build them in the first place.

As for how it works well if you clean the pieces like you would for TIG then apply the flux your home free. The main thing is to use a lower temperature diffused flame source for the heat and bring the temp up slowly. In other words a propane or mapp torch works better than a oxy-acet torch for lighter work. The oxy-acet torch is to hot and will melt the surface before the heat gets a chance to soak into the piece. Alloy 31 will flow about as well as most silver solders.

Another thought is that they sell it in a powdered form already mixed with the flux so all you have to do is brush it on and heat it. I've not used that form so I can't vouch for how well it works.

Wayne Cook Shamrock, TX

Perhaps solder would be a better description for it.

Actually looking up some definitions

it appears they refer to brazing as a soldering process with a hard solder and capillary action. They seem to distinguish soldering as having filler material with melt temperatures below 800F and brazing with melt temperatures above 800F but still below the melt temperature of the base material.

Above 800F and below the 1,100F or so to melt the aluminum must make this aluminum solder / brazing rod a bit tricky to use.

Pete C.

It seems to me that if you can use MIG it might be a better choice. It is fast and certainly possible to do with 1/8th material. Randy

For strength I need to weld a fair amount of these 90 degree crossings, so that would basically be a weld in 1/8" material maximum 1" long.

Well, getting close to the edge is not such a great idea so the welds are actually more like 1/2" to 3/4" long.

They ought to provide strength but they also have to look good!!

Here is what I find: I have a hard time to have the initial puddle connect quickly with both sides of the V shaped trough I am welding in, it always takes me a moment of struggle to have the puddle go to BOTH sides, not only to one, it seems to prefer one side though.

I find it a challenge to make such short and nice welds, often by the time I connect both sides with my puddle the overall size of the area affected is larger than I had intended to.

So here is my question, how do I get the smallest and deepest short weld in this situation??

I use a pure tungsten electrode, 3/32", 1/16" aluminum wire with 110 A AC, a number 7 ceramic cup and 25cbft. of flow.

TIA Uwe

There's definitely lots of rods out there that solder would better describe. Most of those are high zinc rods.

It can be but with care it works pretty well. I've done things with it that amaze me.

Here's a link to it.

Wayne Cook Shamrock, TX

I would try a 1/16 electrode, #5 cup and 15 CFH and 60-75 amps (ACHF). Wooden pencil angle on the electrode.

These should slow the process a bit so that you have time work the puddle.

JAMW

Not knowing what machine you have, I'll say what I believe would be great for this weld. An inverter machine that you can adjust the DC+ & DC- sides of the AC cycle. Such as a Miller Aerowave. I'd use Zirconium tungsten ground to a point, then a small flat. Machine settings of low DC+ amps and higher DC- amps for penetration. And adjust the arc balance in favor of the DC - side. Also consider using argon/helium shielding.

If your machine has an arc balance set it for max penetration and use the argon helium. If you don't have Zirconium, choose 2% over pure tungsten, I know it'll need to be sharpen more, but you can sharpen it for better arc characteristics that the pure can't touch. The only time I've used pure tungsten was when nothing else is available. IMHO pure tungsten is out dated.

Richard